HP 3000 Manuals HP 3000 Manuals
Modulus 10 Self-Check Digit
To calculate the modulus 10 self-check digit, follow these steps:
1. Multiply the rightmost position and every other position, moving
to the left, of the number by 2.
Example: If your number is 1 2 3 4 5 6 7, multiply the digits 7,
5, 3, and 1 by 2 to get the numbers 14, 10, 6, and 2.
2. Add the digits of the products obtained from step 1 above to the
digits that were not multiplied.
Example: The products obtained from step 1 above are 14, 10, 6,
and 2; the digits that were not multiplied are 2, 4, and 6. Add
all these digits: 1 + 4 + 1 + 0 + 6 + 2 + 2 + 4 + 6 = 26.
3. Subtract the value obtained in step 2 from the next higher
multiple of 10; the result is the self-check digit.
Example: The next higher multiple of 10 from the result 26
obtained in step 2 above is 30. Subtracting 26 from 30 gives the
result of 4, which is the self-check digit.
4. The check digit is then appended to the right end of the number to
create the final result.